The NFL's 2018 offseason will feature the rarest of moments: an upper-level quarterback hitting the free-agent market in the prime of his career. Kirk Cousins, who has spent the past two years playing as the Washington Redskins' franchise player, is now on the way out with Alex Smith on his way in.

Anticipation over Cousins' availability, and presumably precedent-setting price tag, clouds what could be an unusually deep free-agent class. The following is a ranking of the NFL's 50 most notable players with expiring contracts.

Keep in mind several won't be on this list in March. Some could face the franchise tag when the franchise/transition period begins Feb. 20, while others could re-sign with their current teams before the market opens on March 12.

Editor's note: Players will be moved to the bottom list as they're signed or tagged.

After two years under the franchise tag, with combined earnings of nearly $44 million, Cousins is primed to experience a rarity for upper-level quarterbacks: a true bidding war for his services. He'll set a new bar for NFL contracts.

After playing 2017 on the franchise tag, Bell told ESPN that he was prepared to sit out the coming season if he is tagged again. Time has a way of modifying such threats. If Bell signs a 2018 franchise tag, he would have earned more than $25 million over two years. But if he's serious about his threat, it might be a rare opportunity to acquire a potential Hall of Fame player at the age of 26.

Insider

Where's Le'Veon Bell? What about Drew Brees? Case Keenum? Sam Bradford? To see how Kevin Seifert ranked the other top free agents, sign up to be an ESPN Insider.